With development of a mobile communications system, the system can provide an increasingly high transmission rate and increasingly high service quality, but user services also impose an increasingly high requirement on the transmission rate. To ensure a rate for general users without a substantial increase in a configured bandwidth, and also provide a higher throughput to some users, a carrier aggregation (Carrier Aggregation, “CA” for short) technology is introduced in the 3rd Generation Partnership Project (3rd Generation Partnership Project, “3GPP” for short). The carrier aggregation technology refers to that user equipment (User Equipment, “UE” for short) may simultaneously use multiple component carriers (Component Carrier, “CC” for short) to perform uplink or downlink communication, so as to support high speed data transmission. When a user rate decreases, some component carriers may be released, and only one resident carrier is reserved. A released transmission resource can be used by another user, thereby achieving an objective of flexibly and dynamically using a network resource.
Long Term Evolution (Long Term Evolution, “LTE” for short) is Long Term Evolution (Long Term Evolution) in a Universal Mobile Telecommunications System (Universal Mobile Telecommunication System, “UMTS” for short) technology that is specified by the 3GPP organization. Carrier aggregation of an LTE system may be roughly classified into intra-base station cell aggregation, inter-base station cell aggregation, and the like. Release Release-10 of the 3GPP supports the intra-base station cell aggregation. The inter-base station cell aggregation may be further classified into cell aggregation between macro base stations and cell aggregation between a macro base station and a small cell (Small Cell). The cell aggregation between macro base stations can improve a data throughput of a user at an edge of the base station, thereby improving user experience. In addition to improvement of a data throughput of a user, the aggregation between a macro base station and a small cell can further reduce system load of a network of the macro base station, and also reduce occurrence of a handover compared with a pure small cell. This technology is generally referred to as a Multiple Stream Aggregation technology (Multiple Stream Aggregation, “MSA” for short).
In a current carrier aggregation technology, users are all connected to the Internet by using a core network of an operator. Therefore, increases in a quantity of users and data traffic result in heavy load of the core network of the operator.